1. Field of the Invention
The present invention relates to a cathode ray tube (CRT), and more particularly, to a CRT that can prevent a glass tube thereof from scattering into pieces when the glass tube is broken or cracked.
2. Description of the Related Art
Generally, a typical CRT includes a glass tube having a panel, a funnel and a neck. The glass tube is evacuated to be in a vacuum state so that electrons emitted from the electron gun can excite phosphors formed on an inner surface of the panel to realize the desired images.
When a mechanical or thermal impact is applied to the CRT under the atmospheric pressure, the glass tube of the CRT may be cracked or broken into many small pieces that scatter.
The scattering of the small pieces of the broken glass tube may be from the side of the panel or the side of the funnel depending on the shape of the glass tube or the stress applied to the glass tube.
In order to solve such a problem, a shrinkage band having a predetermined tension is installed on a skirt of the panel considering that the stress is concentrated on the skirt of the panel. With this structure, when the skirt is cracked by the mechanical or thermal impact, the shrinkage band prevents the cracks from progressing to other portions, thereby preventing the glass tube from breaking and scattering into the small pieces.
Recently, the CRTs have been developed to be slimmer so that they can compete with flat displays such as a plasma display panel (PDP), a liquid crystal display (LCD) or an organic light emitting diode (OLED). In this case, the length of the funnel is reduced as compared to that of the conventional CRT and thus the stress distribution of the glass tube varies.
Accordingly, when the mechanical or thermal impact is applied to the slimmed CRT, the funnel may be cracked due to the varied stress distribution of the glass tube. Therefore, the small pieces of the cracked funnel are liable to scatter toward the panel.
Since the shrinkage band is mounted on only the skirt of the panel, it cannot sufficiently prevent the cracked funnel from breaking and scattering into the small pieces.
Alternatively, efforts have been made to prevent the glass tube from cracking and scattering into the small pieces by attaching a film to the panel. However, such a film is not enough to prevent the scattering of the glass pieces created by the cracked funnel. Furthermore, the film is expensive, thereby increasing the manufacturing costs of the CRT.